Both Russia and Iran, which are the chief guarantors of the latest Syrian ceasefire along with Turkey, have been concerned about the threat the recent US strike on Syria posed to efforts at resolving the country's six-year war.

SYRIA SETTLEMENT

The talks will mainly deal with the military and political situation in Syria, with participants set to discuss trilateral coordination efforts to prevent the situation from deteriorating and undermining the Syrian settlement process in the wake of US strikes against Syrian forces in retaliation for the alleged Idlib chemical attack, according to the Russian Foreign Ministry.

The situation around war-torn Syria became even more complicated after Syrian opposition allegations, made on April 4, that a chemical weapon attack took place in Syria’s Idlib province. World Health Organization (WHO) data indicated that 84 people, including 27 children died as a result of the incident. Western powers followed Syrian National Coalition of Revolutionary and Opposition Forces claims and accused the Syrian government of carrying out the attack.

Syria denied having any chemical weapons at its disposal, while Russia called for a proper investigation into the incident and said it appeared to be the result of a strike on a militant chemical weapons cache by Syrian jets. Despite the lack of clarity, the incident was used as pretext for the US missile strike against the Ash Sha’irat airbase carried out late on April 6. US President Donald Trump characterized the strike as a response to the alleged use of chemical weapons by the Syrian government troops, while Lavrov said it was a violation of international law.

Earlier this week, Syrian Ambassador to Russia Riyad Haddad told Sputnik that more frequent visits by Muallem to Moscow would be a natural result of an increasingly difficult situation in the region.

Muallem had a bilateral meeting with Lavrov ahead of Friday's talks after arriving to Moscow on Thursday.

MEDIATORS

The incident came just as parties to the Syrian conflict started to make meaningful progress at the Geneva peace talks as well as the ceasefire monitoring talks in Astana. Russia, Turkey and Iran are acting as the ceasefire guarantors.

Russian Deputy UN Ambassador Vladimir Safronkov accused Western powers of trying to undermine UN-backed settlement efforts after a vetoed draft resolution, submitted by the United Kingdom, France and the United States, called for the condemnation of the alleged chemical attack.

The United States has insisted that it was justified in hitting the Sha’irat base. US State Secretary Rex Tillerson reiterated that the United States believes Damascus to be behind the attack during his meeting with Lavrov on Wednesday. Tillerson, however, expressed willingness to support an investigation into the Idlib incident by the United Nations and the Organization for the Prohibition of Chemical Weapons.

On Friday, mediators Russia and Iran will talk with their Syrian colleague on how to lower the impact the situation has on Syrian settlement.

The three sides will consider joint steps to minimize the negative consequences of the "gross violation of international law" as well as the threat to international and regional peace and security that the US strike amounted to, the Russian Foreign Ministry said.

Friday's talks will also go beyond the pressing diplomatic issues and will deal with trilateral relations at a deeper level.

On Tuesday, chairman of the Russian State Duma International Affairs Committee Leonid Slutsky said that a permanent parliamentary trilateral committee composed of Russian, Syrian and Iranian lawmakers may be established in the near future, with the decision expected to be made after the trilateral talks on April 14.